BNC installation

"3) Male/Female versus Two Males with coupler (whoa!) - Stick with the
fewest possible connections. Not only for the fact that there are
fewer things to go wrong but because each extra connection looses 2db
(rule of thumb) of your power."

Comment: While I am not an authority on connector loss, my opinion is that
the estimated 2 db loss per connector is high. I have built an EME (Earth -
Moon - Earth) communicatons system where an extra .1 db loss is the
difference between success and failure and carefully monitored losses. It
is easy to measure the loss in connectors and it is rare that 2 db is lost
on the relatively low frequency of 123 MHz. I think the norm is .1 to .2 db
per BNC connector. However, I had a box of short BNC jumper cables
(commercially made) and about one in 10 had a 2 db loss. I have never
determined why and simply discarded the high loss jumpers.

I checked a number of source books to see if I could find any defninitive
statement about "average" loss per connector at a certain frequency, and
could not find any.

The type of BNC connectors that are assembled by screwing together are much
more likely to have high losses than a properly crimped connector.

Colin Lamb

On Jun 25, 7:56*am, "COLIN LAMB" wrote:
"3) Male/Female versus Two Males with coupler (whoa!) - Stick with the
fewest possible connections. *Not only for the fact that there are
fewer things to go wrong but because each extra connection looses 2db
(rule of thumb) of your power."

Comment: While I am not an authority on connector loss, my opinion is that
the estimated 2 db loss per connector is high. *I have built an EME (Earth -
Moon - Earth) communicatons system where an extra .1 db loss is the
difference between success and failure and carefully monitored losses. *It
is easy to measure the loss in connectors and it is rare that 2 db is lost
on the relatively low frequency of 123 MHz. *I think the norm is .1 to ..2 db
per BNC connector. *However, I had a box of short BNC jumper cables
(commercially made) and about one in 10 had a 2 db loss. *I have never
determined why and simply discarded the high loss jumpers.

I checked a number of source books to see if I could find any defninitive
statement about "average" loss per connector at a certain frequency, and
could not find any.

The type of BNC connectors that are assembled by screwing together are much
more likely to have high losses than a properly crimped connector.

Colin Lamb

Colin, he was making a JOKE about various Male/Female ratios etc.
I work instrumentation on military aircraft. Mil spec connectors,
crimpers, etc. Done correctly, soldered connectors and crimped
connectors are equally good. Done badly, neither is worth the trouble
they'll cause. That said, it is EASIER to assemble a soldered
connector BADLY, so crimping (with GOOD tools) would be my choice if I
actually GOT a choice.